$ java CyclicBarrierPipeline

worker-0: finished round 1
worker-1: finished round 1
worker-2: finished round 1
worker-3: finished round 1
barrier action: round 1 complete, all 4 workers arrived
worker-0: finished round 2
worker-1: finished round 2
worker-2: finished round 2
worker-3: finished round 2
barrier action: round 2 complete, all 4 workers arrived
worker-0: finished round 3
worker-1: finished round 3
worker-2: finished round 3
worker-3: finished round 3
barrier action: round 3 complete, all 4 workers arrived
done